Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi
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Zhonghua Liu Xing Bing Xue Za Zhi · Apr 2020
[Epidemic characteristics and trend analysis of the COVID-19 in Hubei province].
Objective: By describing and analyzing the epidemic characteristics and trends of the attack rate, the crude mortality and relevant indexes in Hubei province during the pandemic of COVID-19 to provide comprehensive evaluations of the epidemic trends and the effects of intervention measures. Methods: Based on the case data reported in Hubei province during the COVID-19 epidemic, combined with the important time of major interventions and event, the cumulative attack rate, the sequential increase rate of new cases, baseline increase rate of new cases, the observation- confirmed case conversion rate, the cumulative crude mortality, the daily severe case rate, and the ratio of death to severe were used to describe and analyze the epidemic characteristics in different phases of the COVID-19 epidemic. Results: The epidemic experienced an outbreak phase from January 10 to February 3 with large amount of case reported, a peak phase from February 4 to February 19 with continuous increasing number of new cases and deaths, a platform phase from February 20 to March 3 with balanced diagnosis and treatment number, and a descending phase from March 4 to March 18 with decreased diagnosis and increased treatment number. ⋯ The ratio of death to severe decreased from 7.37% on January 23 to 0.35% on March 18. Conclusions: The epidemic cycle of COVID-19 in Hubei province proposed to be 60 days, which was about 1.76 times of the combination of the longest incubation period or isolation period (14 d) and the average hospitalization time of confirmed patients in Hubei province (20 d). It suggested that the major anti-epidemic decisions made in China were effective.
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Zhonghua Liu Xing Bing Xue Za Zhi · Apr 2020
[Estimating the basic reproduction number of COVID-19 in Wuhan, China].
Objective: The number of confirmed and suspected cases of the COVID-19 in Hubei province is still increasing. However, the estimations of the basic reproduction number of COVID-19 varied greatly across studies. The objectives of this study are 1) to estimate the basic reproduction number (R(0)) of COVID-19 reflecting the infectiousness of the virus and 2) to assess the effectiveness of a range of controlling intervention. ⋯ The R(0) was estimated to be 2.95 (95%CI: 2.86-3.03) after taking control measures. Conclusions: In the early stage of the epidemic, it is appropriate to estimate R(0) using the EG method. Meanwhile, timely and effective control measures were warranted to further reduce the spread of COVID-19.
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Zhonghua Liu Xing Bing Xue Za Zhi · Apr 2020
[Epidemiological analysis on a family cluster of COVID-19].
Objective: To understand the possible transmission route of a family cluster of COVID-19 in Zhengzhou and the potential infectivity of COVID-19 in incubation period, and provide scientific evidence for the timely control of infectious source and curb the spread of the epidemic. Methods: Epidemiological investigation was conducted for a family cluster of COVID-19 (8 cases) with descriptive epidemiological method, and respiratory tract samples of the cases were collected for the nucleic acid detection of virus by RT-PCR. ⋯ Conclusions: In this family cluster of COVID-19, six family members were infected through common family exposure to the 2 primary cases. Five secondary cases had onsets earlier than or on the same day as the primary cases, indicating that COVID-19 is contagious in incubation period, and the home isolation in the early phase of the epidemic might lead to the risk of family cluster of COVID-19.
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Zhonghua Liu Xing Bing Xue Za Zhi · Apr 2020
[Dynamic basic reproduction number based evaluation for current prevention and control of COVID-19 outbreak in China].
Objective: To evaluate the current status of the prevention and control of coronavirus disease (COVID-19) outbreak in China, establish a predictive model to evaluate the effects of the current prevention and control strategies, and provide scientific information for decision-making departments. Methods: Based on the epidemic data of COVID-19 openly accessed from national health authorities, we estimated the dynamic basic reproduction number R(0)(t) to evaluate the effects of the current COVID-19 prevention and control strategies in all the provinces (municipalities and autonomous regions) as well as in Wuhan and the changes in infectivity of COVID-19 over time. Results: For the stability of the results, 24 provinces (municipality) with more than 100 confirmed COVID-19 cases were included in the analysis. ⋯ By the time of data analysis, 18 provinces (municipality) (75%) had the R(0)(t)s less than 1. The results could be used for the decision making to free population floating conditionally. Conclusions: Dynamic R(0)(t) is useful in the evaluation of the change in infectivity of COVID-19, the prevention and control strategies for the COVID-19 outbreak have shown preliminary effects, if continues, it is expected to control the COVID-19 outbreak in China in near future.
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Zhonghua Liu Xing Bing Xue Za Zhi · Apr 2020
[Fitting and forecasting the trend of COVID-19 by SEIR(+CAQ) dynamic model].
Objectives: Fitting and forecasting the trend of COVID-19 epidemics. Methods: Based on SEIR dynamic model, considering the COVID-19 transmission mechanism, infection spectrum and prevention and control procedures, we developed SEIR(+CAQ) dynamic model to fit the frequencies of laboratory confirmed cases obtained from the government official websites. The data from January 20, 2020 to February 7, 2020 were used to fit the model, while the left data between February 8-12 were used to evaluate the quality of forecasting. ⋯ Regardless of the cases diagnosed by clinical examines, the numbers of daily emerging cases of China (Hubei province not included), Hubei Province (Wuhan city not included) and Wuhan city reached the peak in the early February. Under the current strength of prevention and control, the total number of laboratory-confirmed cases in overall China will reach 80 417 till February 29, 2020, respectively. Conclusions: The proposed SEIR(+CAQ) dynamic model fits and forecasts the trend of novel coronavirus pneumonia well and provides evidence for decision making.